Device for overcoming effects of shocks



DEVICE FOR OVERCOMING EFFECTS OF SHOCKS Filed May 12, 1943 ZSheets-Sheet 1 INVENTOR. f'flw/wr 6'. 106a BY Sept. 18, 1945. G, LOGAN 2,385,293

DEVICE FOR OVERCOMING EFFECTS OF SHOCKS Filed May 12, 1945 2 Sheets-Sheet 2 Y 613V 2 UV TOR.

RAN/f 6/9 44M. nrraxrxygy Patented Sept. 18, 1945 DEVICE FOR OVERCOMING. EFFECTS OF SHOCKS I Frank G. Logan, Mount Vernon, N. Y., assignor to Ward Leonard Electric Company, a corporation of New York Application May 12, 1943, Serial No. 486,689

6 Claims,

This invention relates to mechanisms, suchas electric'switches and the like, which are movable to different positions, such as the open and closed position of a switch; circuit breaker, relay or other devices, and restrained in one of the posie tions by a latch or otherwise. Such mechanisms are released by a controlled .movable element which is adapted to engage and release the latch .or other restraining means upon the occurrence of a certain condition or certain conditions. For example, an overload relay is adapted to attract itsmovable armature or plunger and release the restraining means upon the occurrence of an overload current.

Mechanisms of this character when used in locations which are subject to mechanical shocks or jars are likely to be tripped or released by causingthe movable element to be thrown against the releasing means and thereby cause an undesired tripping of the mechanism. It has been proposed to overcome this undesired action by providing an additional movable element which is normally at rest but which, under shock, would strike the restraining latch on the opposite side of the pivot of the latch from that engaged by the movable element of the mechanism and thereby prevent the latchfrom being tripped. However, in many cases the weight or mass of the counter-acting element required to overcome the effect of the force of the tripping element is quite considerable, resulting in considerably increasing the total weight of the parts and the space occupied.

By the present invention, instead of attempting to provide a movable mass sufiicient in the force exerted thereby to overcome the force of the movable releasing element, a movable device is utilized which is controlled by the movement of a comparatively small mass which serves to lock the restraining means against release under shocks. That is, in the caseof a restraining latch, the small movable mass causes an element to be moved to a position which will prevent the release of the latch.

The main object of the invention is to provide means for overcoming the effects of shocks which will be simple in character, of comparatively small weight and size and dependable in operation. Another object is to provide means Which may be applied readily to various types of mechanisms without the necessity of radical change in the design of the parts and which, in some cases, may be addedto existing mechanisms. Another object is to produce an auxiliary device which may be made at small cost and readily assembled. Other objects and advantages will be understood fromthe following description and accompanying drawingswhich illustrate oneembodiment of the invention applied to a relay.

Fig. 1 is a side view partly in section showing the parts in their restrainedpcsition; Fig. 2 is a vertical section of a portion'of the parts showing them inthe-ir released position; Fig. 3 is a top plan view of a portion of the-relay with one of the parts broken away; and Fig.4 is avertical section onthe. line 4-4 of Fig.3.

The particular relay shown is'or" the type disclosed inthe Kouyoumjian Patent No. 2,308,660 grantedJanuary 19, 1943 andforms no part of the, present invention. It is sufficient to explain for present purposes that it has a magnet frame I and an exciting winding 2 which when sufliciently energized will attract and raise a movable element 3. This then moves the rod 4 upwardly which trips thepivoted latch 5 and releases the restrained element 6. This is acontact element biased to open position by aspring l tendingto separateits movable contact 8, from the fixed contact ,9. After. opening, the contacts may be reclosed manually against the pressure of the spring by theihandle ii). The parts are then restrained in closed positionby the latch-5 which engages a disk. H fixed to the rod-6 Instead of closing contacts in the restrained position, the device may bearranged to open contacts in the restrained position and close them in the released position or variouslycontrol contacts in the different positions; or the controlled element may serve to actuate any-mechanical means for any desired purpose. Instead of using an electromagnet for tripping theholding means, any other form of device having a. movable element may be used for releasing. the. restrained element.

It is apparent that the movable element 3 and the rod 4 may be actuated, under mechanical shocksor jars imposedupon-the device, to move upwardly with reference to their Support and thereby actuate the latch torelease the parts. Suchv an improper actuation of the releasing means would. be highly undesirable because the parts shOuld ,be released only when-the predeterminedconditions occur for such release by sufiic-ientenergization of the magnet. Any improper release of the restrainedpartsisavoided by the present invention.

Fig. 1 shows. the parts in the restrained position, the latch 5 being biased to latching position by a spring I 2 encircling the shaft on which the latch is mounted which spring has extending portionstending to turn the latch in a clockwise direction. A stop l2a turned up from themetal plate I3 serves to limit the movement of the latch in a clockwise direction when released from the minal connection l3d. A flexible lead I4 con nects the plate electrically with the rod 6.- The fixed contact 9 is supported by a flexible leaf spring 9a which in turn is connected electrically to a terminal 9?) mounted upon the base I5 of insulatingmaterial. A pin I6 is fixed to the rod 6 and extends downwardly into a slot formed between a pair of upwardly extending portions I5a from the base I5. The pin I6 in its movement in this slot serves to guide the contact end of the rod 6; and when the parts are released, the pin I6 serves as a stop to limit the outward movement of the rod 6 by engaging the plate portionj3b. 7

The means for overcoming the effects of shocks and preventing the improper'release of the restrained parts is shown in the present instance as comprising a cross piece I I of insulating. material which, as'well shown in Fig. 4, is supported at its opposite ends by sleeves I8 ofinsulating material, the parts being secured to the base l5 by the screw bolts I9. Instead of making the cross bridge and supporting sleeves of insulating material, they may be made of metal if desired. A central portion on the underside of the bridge II-iscut away, as shown in Figs. 2 and 4, and a weight or massZU extends partially within the opening. This mass is pivotally mounted at its inner-end on a rod 2|, the ends of which rod aresupported by extending within the bridge I'I. Fixed to the inner end of the mass 20, or forming apart thereof, is a downwardly extending plate 20a which passes by the rod 6 and is provided with a tongue or extension 201), as well shownin Fig. 4. The normal position of the extensionjmb is above and beyond the inner end or tail of 'the'latch 5, as shown in Fig. 2 and in full lines in Fig. 1. The weight of the mass 20 normally holds the extension 20b in this position against the portion l3b of the metal plate. It i's-therefore apparent in theabsence of any shocks, the projection or element 2% is out of thepath of movement of the tail of the latch, permitting the latch to be tripped by the upward movement of the element 4 upon the occurrence f a predetermined condition, such as an overload current in the relay. 7 When, however, a mechanical shock or series of shocks, occurs which would impart an upward movement to the element 4 and thereby improperly trip the latch, the mass 20 and the element 201) serve to'prevent such improper release of the parts. This is due-to the fact that any mechanical sh'ock which would move the rod 4 and plunger 3 upwardly, would likewise move the mas 20 upwardly, turning'oii its pivot in a clockwise direction and thereby bringing the element 2Ib over the tail of the latch and prevent its tripping by the movable element of the relay. Also, the distancefrom the" pivot of the mass to the lower end of the locking element 2% is greater than the distance fromth'e pivot of the mass to the center of gravity of the mass'which results in a comparatively I small movement of the mass, "giving an amplified movement of the locking element over assent V J F the tail of the latch. It follows that the latch will thus be locked against release before it is subjected to the impact of the movable element of the relay; and the parts are related so that only slight movement or the element 20?) from its normal position is required to arrive at a looking position over the tail of the latch. Fig. 1 shows in dotted lines the extreme locking position of the mass and its locking element but it is apparent that the latch will be locked from disengagement as soon as the edge of the locking element passes over the edge of the tail of the latch. After the passage of the shock or shocks the mass 20 will fall to its normal position and swing the locking element out of the path of the latch, thus permitting the relay to function in its intended manner upon the occurrence of an abnormal condition, such as an overload current. The parts may be variously arranged in their relationship to each other for attaining the objects of the invention and adapted to various types of devices which are restrained in one position and biased to move'to another position when the restraining means is released by a movable element. 7

Although a particular embodiment of the invention has been .described, it will be understood that various modifications may be made for adaptation to particular requirements without departing from the scope of the invention.

I claim:

l. The combination of a movable device biased to move from a restrained position, means for holding the device in the restrained position against its biased movement, an element movable independently of said means for releasing said means, said element being subject to movement by mechanical shocks, means for actuating said element forreleasing said holding means, and

means havin a pivotal support movable under shock for locking said holding means from movement by said movable element until thepassage of the shock.

2. The combination of a movable device biased to move from a restrained position, means for holding 'the device in the-restrained position against its biased movement, an element movable independently of said means for releasing said means, said element being subject to movement by mechanical shocks, means for actuating said element for releasing said holding means, a fixed support, and an element movable under shock to a position supported between said fixed support and said holding means for locking said holding means from movement by said first named mov able element until the passage of the shock; V

3., The combination of a movable device biased to move from a restrained position, mean s for holdin the device in the restrained position against its biased movement, anelement movajble independently of saidmeansfor releasing said means, said element being subject to movement by mechanical shocks, means for actuating said element for releasing said holding means, a fixed supportand a mass pivotally mounted on said support having an extension movable therewith under shock for lockingsaid holding means from movement by said movable element until the passage of the shock. V, r 7 V 7 v 4. The combination of a movable device biased to move from a restrained position, means for holding the device in the restrained position against its biased movement, an element movable independently of said means "for releasing 'said means," said element being subject to movement under shock for locking said holding means from movement by said movable element until the passage of the shock, the distance from the center of gravity of said mass to its pivot being less than the length of said extension.

5. The combination of a movable device biased to move from a restrained position, a latch for holding the device in the restrained position against its biased movement, an element movable an extension movable therewith under shock for locking said latch from movement by said movable element until the passage of the shock.

6. The combination of a movable device biased to move from a restrained latch, said element being subject to movement by mechanical shocks, means for actuating said element for releasing said latch, a fixed support above said latch, and a mass pivotally mounted on said support having a downward extension movable therewith under shock over the tail of the latch for locking the latch frOm movement by said movable element until the passage of the shock.

FRANK G. LOGAN. 

